First off, I want to say how impressed I am that you (OP) have taken the initiative to do WK on top of all your schoolwork and whatever other activities you have going on, so yay you!
I’m a fair few levels behind you, but realised at about lvl 10 that with the kanji getting more complex, simply looking at them during the lessons wasn’t going to make the cut for me, so after seeing Leebo’s post on the Iversen Method, I have started ‘pre-learning’ the radicals and kanji for the next lvl using this method whilst working through the current level on WK - if you have to write out the kanji from memory, you really need to actively KNOW the radicals and the mnemonics. It does initially take more time, but then I’m not spending a bunch of time doing reviews of items that I keep getting wrong, so I think it all balances out.
jprspereira wrote a fantastic bit here about his methodology for using WK, and the bit about timing of lessons and reviews revolutionised the way I use WK and really helped make my time on WK more focused and effective. I now only do lessons at 7am, followed by reviews; further review sessons are at 11am and 7pm (I’ve also thrown in a 3pm session, but it’s usually only a handful of items). If you can find time on your school lunch break to do some reviews, I think that would help balance the load somewhat, instead of only doing 1 or 2 big sessions a day.
You asked about leeches, and I’ve not seen that anyone has directly answered your question: I use both the leech training script and the SRS Level Progress script (the latter is the one that shows your leech numbers on your dashboard) - I use the training script immediately after each review session if it shows that I have leeches.
All the best!